Straightening roll



G. A. WISE STRAIGHTENING ROLL Filed. Feb; 15, 1923 3 Sheets-She's"; 1

660776 A. Wise NW m mm W G. A. WISE STRAIGHTENING ROLL Filed Feb 15, 1923 3 Sheets-Sheet 2 flNVEN? 66075? A e in; 73 WW his art zar r267 tamed Nov. 15, 1927.

UNITED STATES V 1,649,204 PATENT OFFICE.

GEORGE AEWISVE, F PITTSBURGH, PENNSNVANIA, ASSIGNOR' TO SU'TTGIT-.AIBRAJEE-v 'SEN ENGINEERING COMPANY, OF PITTSBURGH, ZPENNSYLVANIA, A CORPORATION or PENNSYLVANIA.

Application iuea February This invention relates to a special roll for use in a machine for the straightening of metallic bars and tubes of circular cross section, for example bars and tubes of steel and aluminum.

- The general type of-machine for use with which the roll of the present invention is particularly designed is that of the machine shown in the atent to'Petter B. Abramsen In No. 1,097,281, ated May 19, 1914. In the accompanying drawings Figure 1 is a front elevation of a straighteningmachine of the general type mentioned above;

a Fig. 2 is a side elevation of a set of straight- 1 ening rolls as mounted in such machine;

Fig. 3 is a plan view of such set of straightening rolls; Fig. 4 is a horizontal section through such set; Fig. 5 is a side elevation, on an enlar ed scale of a straighteningroll made according to the present invention, illustrating the derivation of the curves forming the concave face of the roll, and showing the contact of two bars of different diameter with such face; Fig. 6 is an end elevation of the roll, further illustrating the derivation of the curves forming the face thereof, and showing the contact of the twor bars with the face of the roll at different points therealong; and Fig. 7 is a mathematical m diagram illustrating graphically the deriva- Clofil of the curves forming the face of the ro V In such machines the bars and tubes are carried between positively driven rolls, having concave faces, and smaller idler rolls the faces of ,which are also concave. Both the driven rolls and the idler rolls are set in theframe or housing of the machine at an angle to the horizontal determined with reference to the diameter of the bars undergoing a straightening operation. IIl'QODdUClZHIg a straightening operation it is highl important that the bar passing through t e machine should have a line rather than a point contact with the face of each of the main or driven rolls, such line contact extending a considerable proportion of the'len th of the face. Failure to provi'de such ine contact results in scrolling, the surface of the bar, that is in imposing upon the surface of the metal a spiral twist. Previously therefore, it has been a practical necessity to change the angle at which the rolls are mounted in the housin in order to adjust the machine for the straightening i STRAIGHTENING ROLL.

15, 1923. Serial no. v619,113.

It is also a fact that when a line contact is provided there is a tendency, particularly before the rolls have been worn in,'for the extremities of the bars to be 'kinked owing to the fact that they do not immediately center themselves in passing from roll to an appreciable quantity of metal cut from the endsfof the bars.

One object of the present inventionis to provide a roll having a face so formed that bars of various diameters, within the limits for which each particular roll is formed, will roll. These kinks require the scrapping of c have a true line contact of adequate extent therewith.

Another object of the invention is to provide a roll so formed that bars may center. themselves on the faces of successive rolls and pass smoothly through the machine without'such buckling or snappinglas would i tend to produce kinks or tremities of the bars. A The manner of attaining thefirst object, generally stated, is to form the face of the roll on a plurality of arcs intersecting at a point or points part-way of the length of the roll, so that bars of difierent diameter may find their line contact on different 'portions'of the roll.

The manner of attaining the second objct, enerally stated, is to so form the roll that the diameter at one end of the face thereof is slightly reater than the diameter at the other end 0% the face. This also 0bviates the disadvantage of a slight ridge or peripheral rib, which would otherwise be bends in the ex- 1 present at the point of intersection of the presents a combination of both such advan- Although the roll'as shownanddescribed ice tages, it will be seen subsequently herein that a roll may be made which presents either of such advantages alone.

As shown in Figs. 1 to 4: inclusive of the drawings, the arrangement of a machinemay be such that two ositively driven rolls 1, such as those of t e presentinvention, are f I mounted inseries in the frame of the machine at an angle to the horizontal. operating with these positivelydrit enrolls Go f 1 are smaller idler rolls 2, which are mounted at an equal and opposite angle to the horizontal. In the set of rolls shown three eter, and that the roll be mounted at an angle Q to the horizontal.

\Vith reference to Figs. 5 and 6 of the of such idler rolls 2 are employed; one of drawings, this formula is as follows:

such rolls being mounted opposite each of the main. rolls'l, and a third idler being mounted intermediately thereof. As the bar 3 passes through the machine it is gripped by the rolls in the manner shown in Figs. 3

and 4. of the drawings.

As shown diagrammaticall in Figs. 5 and 6 of the drawings, bars of di erent diameter find their line contact with different por-' tions of the face 4 of the roll. In Fig. 5 a bar 5 of the maximum diameter which the particular roll shown is designed to accommodate is shownin contact with the face of the roll, and a bar 6 of the minimum diameter which the roll shown is designed to ac- 'commodateis also shown in contact with the face thereof. Approximately only such portions ofeach bar as actually lie in contact with the face 4 of the roll areshown in this figure of the drawings. In Fig. 6 the same two bars 5 and 6 are shown in contact with the face of the roll. In this figure, however, the bars are shown in duplicate; the diagrammatic representation of the bar 5 designated 5 indicating the contact of the bar with the circumference a (or diameter' Dw) of the roll, and the representation designated 5 indicating the contact of the bar with the circumference b (or minimum diameter) of-the roll. Similarly the diagrammatic representation 6" indicates the contact of the smaller bar 6'with the circumference b (or minimum diameter) of the roll, and the representation 6 indicates the contact of such bar with the circumference c (olr1 maximum diameter D max) of the re These figures represent the positions of bars of four inch diameter and of a two inch diameter in their contact with the face of.

a roll designed specially to accommodate bars of a dlameter within these limits. If the diameter of a bar passing through the rolls be of a diameter between four nches and two inches, its line of contact will obviously be intermediate that of the bars of extreme diameter shown, and will partiall overlap the lines of contact of both thereo For the format'i'on'of a roll of the type shown a general formula has'been deduced. That is, within limits, this formula may be applied for the formation of a roll accommodated to bars having certain extremes of diameter, and to bars of diameters intermediate these extremes. The general characteristics of such roll are that its face he formed on two intersecting curves which are the arcs of circles; because of the desirability for a lessendiameter at the entering than at the leaving end of the roll, that these arcs be those of circles of different diam- In the foregoing formula C is a constant comprising the product of one half the total line contact of the face'of the roll and the tangent of the angle atwhich the -roll is set to the horizontal.

R min is the least radius of the face of the roll, occurring at the median cross sectional line thereof. It is the square root of the square of the sum of the greatest radius of the face of the roll 'R max and the radius of the bar of least diameter which the roll may accommodate g, minus the square of C, or the product of one half the total line contact and the tangent of the angle Q, which the axis of the roll forms with the horizontal; less the radius of the .face of the roll and the radius 5 of the bar of greatest diameter which the roll may accommodate, plus the square of C or the product of one half the total line contact and the tangent of the angle Q, which the axis of the roll forms-with the'horizontal;

H less the radius of the bar of greatest Y 2 diameter.

S is a quantity representin the difference of the greatest radius of t e roll face.

; inches. able condltion for such range,D max 1s.

see

that the leaving end thereof, and the least radius of the roll.

T is a quantity representing the difier ence of the radius of the roll at the entering end thereof and the least radius of the roll.

Radius A, derived as indicated in the formula, is the radius on which the rearward half of the roll is turned.

Radius B, derived as indicated in the formula, is the radius on which the forward or entering half of the roll is turned.

The following concrete example is derived by substituting in the formula the definite figure for a particular roll. Such roll, which is the one specifically illustrated herein, is a roll designed to provide line contacts for bars of from two inches to four In order to secure the most favoreleven and onefourth inches (11 the total length of the double line contact is sixteen and one-half inches (16 and the angle Q, formed by the center line of the roll with the horizontal of the pass is twenty degrees (20).

With "these substitutions the formula for the roll shown would read as follows:

It will he seen that the formula given is such as to provide for any bar within the desired limits a line contact equal to onehalf the entire face of the roll, as is shown in Fig. 5 of the drawings. That is, during rotation of the roll the bar has such a line contact at any instant with some line oi points on the surface of the roll. This is obviously themaximuni line contact which can be provided for uni-cross sectional bars of various diameters within the limits tor which the roll is designed.

It should also he understood that the essence of the present invention resides in the provision of the plural line contact along the face of the roll and in the various diameters thereof, and not in the specific. formulafor the 'formation of any particular roll. A numberof variations in the roll are, therefore, within the knowledge and power of a skilled mechanical engineer and mathematician without departing from the spirit of the invention.- Thus the roll'may be so formed as to provide a plural instead of a double line contact, or the face of theroll may be formed on curves other than the arcs of circles. r i

The scope of the invention is therefore to. v

be restricted only by. the limitations 0on v GEORGE Afiwisn. 

